Have you ever gone to a seminar or presentation that had people from two different countries attending? You may have, and you may have seen the speaker and also another person on stage talking after the speaker has finished a statement. What the second person does is called consecutive interpreting that is needed to deliver the message to those who do not speak the language of the main speaker.
Interpreting is an important part of many events that involve multilingual people. If an interpreter is not used at such events, not every participant will be able to understand or fully participate. An 
interpreter’s job is to translate and deliver the speech given by the speaker to those who do not understand the speakers language. The responsibility that falls on such an interpreters shoulders is similar to those of the speaker as in essence he is the speaker to those who cannot understand what the key speaker is saying.
Interpreters are normally those who understand a language spoken at an event fluently and would normally translate it into their native tongue. You may see them at many multilingual seminars, big worldwide conferences and sometimes even at churches where a pastor from another country will be preaching to those who do not understand English.
Interpreters carry a large amount of responsibility as they must ensure the message spoken is delivered in the right manner and the right context to those listening. If an interpreter does not translate the message accurately, he or she will in effect be telling a lie or misleading the listeners. Therefore to become an interpreter a person must be 
extremely proficient and have a vast amount of knowledge and education. Even though interpreters may not look that important at such events, they are key to many organizations and bodies around the world.
To become an interpreter a person must not only be a native speaker of his language but must also study and possess a degree in that language. Most interpreters who work for organizations such as the UN, IMF, WHO or other large organizations are extremely educated and have years of experience in interpreting. They cannot do the job if they are not 100% accurate in their translations and work. We often don;t see them but may have seen participants in meetings, and conferences, wearing headsets. This is because, and interpreter is listening to the speaker and translating the message to the listen in a language they can understand.